BARCELONA, Spain -- For about 90 minutes Sunday afternoon, Alfonso Izquierdo used his almost bare hands to slap a small, leather-covered ball -- an object not unlike a baseball -- against a three-walled court that vaguely resembled the Green Monster at Fenway Park.

When he was finished, Izquierdo stripped off about four layers of tape and revealed hands that looked as if air had been pumped into them, they were so swollen. His pinkies were bent inward, as if they grasped an imaginary handball. His skin was blood red.

Izquierdo, a petroleum engineer from Mexico City, is a practitioner of pelota, the most exotic of the three demonstration sports being offered during the Olympics. The others are roller hockey and tae kwon do.

Pelota dates to the 14th century, when it was played in enclosed courtyards and town squares in southern France and northern Spain. It now encompasses a variety of ballgames native to the Basque region of Spain. For Americans, the most familiar of these is jai alai.

Each variation -- there are 10 events in the Olympics -- is a kind of three-walled handball. The differences lie mostly in the size of the court, the hardness of the ball and the equipment the players use to whack it around.

In frontenis, the players use a kind of oversized tennis racket and engage in interminable, almost hypnotically tedious rallies. Pala corta and palette are far more interesting: the helmeted players wield bats that look like enormous serving spoons to bash a ball that looks and sounds like a rock when it crashes against the 33-foot front wall.

Jai alai, in which players whip the ball with a basket glove that extends from their arm, is reputedly the fastest game in the world, with the ball traveling at speeds up to 150 miles per hour.

In the purest -- and oldest -- of the events, however, the players take the court and simply flail away with their hands. The games are almost painful to watch; the players massage their hands between points and sometimes spin all the way around just to get the ball up to the wall.

During a match against France Sunday, Izquierdo, who received little help from his hapless teammate, fired off at least 20 shots with both hands from about 20 yards before losing a five-minute point. He and his teammate lost the match, 22-15.

Asked why he would want to ruin his hands when he could just as easily pick up a racket, Izquierdo said, "Because this is the queen of pelota. It is an entirely different thing to have to hit the ball with a racket than to hit it until your hand is numb and you are doing it with the entire force of your body."

"We feel that this is a beautiful sport," said Jose Gomez, vice president of the International Pelota Federation. "We feel it is at least as beautiful as many of the other sports that are in the Olympics right now. We hope that it can be accepted as an official Olympic sport."

As of now, however, it appears unlikely that pelota will resurface even as a demonstration event. The trend is actually in the other direction; because of the increases in the number of athletes caused by countries splintering and coming back into the Olympic fold, exhibition events are scheduled to be discontinued starting with Atlanta in 1996.

The shift will end a time-honored Olympic tradition of including sports that are either off-beat or reflect the culture of the host country.

Tug-of-war, golf, bowling and motor boating were all once Olympic sports. Live pigeon shooting was part of the Paris competition of 1924. Games like baseball, which became a medal sport this year, tennis and judo were demonstration sports before becoming full-fledged events.

Roller hockey made it in this year in part because Juan Antonio Samaranch, the head of the International Olympic Committee, was once a roller hockey goalie. Tae kwon do was a holdover from the Seoul Games in 1988.

The differences between exhibition sports such as pelota and fringe events like archery and table tennis are obviously minor. But much of it has to do with participation. Pelota, for example, is a major sport in the Basque region but is fairly minor in other parts of Spain, including Barcelona.

Frontenis is huge in Mexico; roughly 4 million people participate, most in schools and private clubs. But it is minor elsewhere. "There is a heart specialist in Arizona who says that frontenis is the perfect sport for people who have had a heart attack," said Gomez.

The faster forms of pelota would seem more attractive than, say, shooting or judo. The cost of participating is fairly prohibitive, however. A ball can run as much as $75. A bat is roughly double that, players said.

In the United States, the game is mostly associated with wagering and, to a certain extent, corruption. As a sport, however, it is exciting on its own. In the faster games like palette, pala corta and jai alai, the players wear helmets. "If the ball hits you, your bones will break," said Roberto Iniestra, 33, a Mexican silk screener whose two-man team advanced to the semifinals.

Fans are vocal. The players are emotional. When Iniestra's team clinched victory Sunday, he tossed his bat away and fell to the ground while his French counterpart fell beside him and lay face first for several moments.